Schools in Florida's second-largest county are on lockdown as a precaution after receiving an unspecified threat.

Broward County schools were locked down Wednesday. The lockdown originated in Pembroke Pines, a Fort Lauderdale suburb, then other schools in the county were locked down. The city's police say it received a possible threat aimed at its schools.

Authorities say an e-mail was also sent saying "something big was going to happen" around Broward's government buildings.

Police say the threat has not been confirmed.

Schools spokeswoman Nadine Drew said the schools are operating as normal as possible.